Here's one I just recommended in another post.
Cute PDF Writer. Its great for creating a pdf file of your document so that the original can't be altered by the recipient. You simply click to print document and select Cute PDF Writer instead of your actual printer, and save to wherever you like.
From their site: Create professional quality PDF files from almost any printable document. FREE for personal, commercial, gov or edu use! No watermarks! No popup Web ads! Now supports 64-bit Windows.